recurring-payment: create_recurring, pause_payment, resume_payment, and cancel_payment emit no events

[gboigwe]

Summary

Only execute_payment emits an event in recurring-payment; the entire lifecycle-management side of the contract (creation, pausing, resuming, cancellation) is silent off-chain.

Location

contracts/recurring-payment/src/lib.rs: create_recurring (~70), pause_payment (~211), resume_payment (~242), cancel_payment (~281) — none emit events; only execute_payment (~137) does.

Problem

An off-chain system tracking a user's recurring payments (a subscription dashboard, for instance) has no way to know when a subscription was created, paused, resumed, or cancelled without polling get_payment for every payment ID of interest — only the periodic execution itself is observable.

Impact

Medium-high: this covers the majority of the contract's state machine (4 of 5 state-mutating functions), including the two most user-facing actions (creating and cancelling a recurring payment).

Acceptance Criteria

• create_recurring, pause_payment, resume_payment, and cancel_payment each emit an event capturing the relevant payment ID and new state
• cargo test -p pulsar-recurring-payment passes

Suggested Approach

Mirror execute_payment's existing event-emission structure for the other four functions.